Sewing-machine shuttle.



No, 797,047. PATENTED AUG. 15, 1905.

O. H: OHITTUM.

SEWING MACHINE SHUTTLE.

APPLICATION FILED JAN.11. 1905. I

13 i4? 2 c/wzw/z Witnesses Httomegs Inventor.

CHARLES H. OHITTUM, OF LEXINGTON, VIRGINIA.

SEWING-MACHINE SHUTTLE.

Specification of Letters Patent.

Patented Aug. 15, 1905.

Application filed January 11, 1905. Serial No. ZMLGSB- To all whom, it may concern.-

Be it known that I, CHARLES H. GHITTUM, a citizen of the United States, residing at Lexington, in the county of Rockbridge and State of Virginia, have invented a new and useful Sewing-Machine Shuttle, of which the following is a specification.

This invention relates to the shuttles of sewing-machines, more particularly to those employed for sewing heavy goodssuch as leather, canvas, and thelikeand has for its object to provide a simply-constructed and easily-applied tension attachment whereby the eificiency is materially increased and the tension for the lower thread adjusted to suit the varying sizes of thread employed.

Another object of the invention is to pro-- it being understood that the invention is not necessarily limited thereto, as various changes in the shape, proportions, and general assemblage of the parts may be resorted to without departing from the principle of the invention or sacrificing any of its advantages.

In the drawings thus employed, Figure 1 is a side elevation from the front. Fig. 2 is a side elevation from the rear. Fig. 3 is a side elevation, partially in section. Fig. 4 is a plan I view. Fig. 5 is a detached perspective view of the tension-spring. Fig. 6 is a detached perspective view of the tension-plate.

To produce the best results in line stitching on leather and like heavy material, the lower or shuttle thread should be of a size corresponding to the upper or needle thread; but heretofore it has been necessaryto use a much coarser thread in the shuttle than in the needle, as the shuttle tension as heretofore constructed is not strong enough to exert pressure suflicient to hold the finer threads and prevent them from being pulled through the material and exposed upon the face side of the same. This is especially objectionable where threads of two colors are employed, as it spoils the symmetry and appearance of the work.

The improved attachment herein shown and described is designed to produce an improved shuttle tension whereby the pressure may be readily adjusted to correspond to the size or quality of the thread employed in the shuttle and to enable a thread to be employed in the shuttle that shall correspond to the thread employed in the needle, and thus produce a uniformity in the stitching upon both sides of the material.

The shuttle portion to which the improved device is attached comprises a shell 10, in which the bobbin or spool 11 is mounted for rotation and bearing against the internal shoulder 12, The shell 10 is provided \vitha fiat-bottomed tension recess or cavity 13, the recess connected by the thread-guiding channel 14 with the interior of the shell and also provided with a thread-guiding channel 15, leading through the front wall of the tensionrecess and opening outwardly therefrom, the channel being enlarged at its inner terminal and leaving a contracted entrance 22, formed obliquely to the longitudinal plane of the shell and bobbin, as shown, the object to be hereinafter explained. Disposed in the recess 13 is a tension-plate 16, secured in place at one end by a clamp-screw l7 and with the free end bent rearwardly, as at 18, and the latter extended, as at 19, opposite the thread-guide 15 to form ayielding closure to the inlet 22 thereof. Bearing upon the tension-plate 16 is a spring 20, with one end secured in position by the clamp-screw 17 and the other end projecting beneath the rearward extension 18. An adjusting-screw 21 is tapped through the spring 20 and bears upon the body of th'e'shell at the bottom of the tension-recess, the tension-plate 16 having an aperture to receive the free end of the ad justing-screw, which is rotative therein. By this means the pressure exerted by the tension may easily be controlled and regulated to any required extent,

the pressure being exerted by a relatively broad flat surface, as will be obvious.

The thread is passed into the channel 14 and thence beneath the end 18 of the tension-plate 16 and thence through the contracted entrance 22 to the guide-channel 15 and into the enlarged terminal of the same and a portion of the thread drawn out to insure the proper position beneath the tension member. The lateral extension 19 of the tension-platel6 hearing against the inner end of the contracted portion of the guide channel 15 forms a yieldable partial closure to the entrance of the channel and effectually holds the thread in the channel and obviates any tendency to jump therefrom while the shuttle is in action. By this means it will be obvious that the thread ing of the shuttle is very much simplified and the annoyance and labor incidental thereto materially decreased.

Heretor'ore the threading of the shuttle has required very careful manipulation of the thread and the passing of thefree end through an eye in one side of the tension-recess requiring great precision of eye and steadiness of the hand to accomplisl1,and when using the coarser threads of silk and the like, such as are used in sewing leather and similar material, the necessity for thus passing the end of the thread through acontracted eye is very annoying and causes vexatious delays. WVith the improved device herein described the threading of the shuttle becomes a very simple matter and can be quickly accomplished with very little use of the eyes of the operator, as the thread very readily follows the path provided for it through the channels and beneath the tensionplate.

The oblique form of the entrance to the channel 15 renders it necessary to turn the thread to one side before it can be entered therein, and as the thread is not turned in that position when in action it will be obvious that it will not be liable to jump from the channel when the shuttle is in use. The lateral projection 19 of the tension plate projecting over the entrance to the oblique portion of the channel 15 effectually prevents any tendency of the thread to leave the guidechannel, no matter how rapid the action may be. The lateral projection 19 therefore is an important feature of the invention and adds materially to the value of the invention.

The tension-plate 16 and spring 20 may be in one single piece of metal, preferably of steel; but this would not be a departure from the principle of the invention, as it would not change the results accomplished.

Having thus described the invention, What is claimed is I 1. The combination with a shuttle-shell having a tension-cavity and with a thread-guiding channel between the tension-cavity and the interior of the shuttle and atransverse threadguiding channel through one of the side Walls of the cavity, a tension-plate disposed within said cavity and formed with a backwardlybent terminal and extended laterally opposite said transverse thread-guide, a spring bearing upon said tension-plate and extended beneath said backwardly-bent portion of the same, and a clamp-screw passing through said tension-plate and spring and into the shuttie-shell.

2. The combination with a shuttle-shell having a tension-cavity and with athreadguiding channel between the tension-cavity and the interior of the shuttle and a transverse threadguiding channel through one of the side walls of the cavity, a tension-plate disposed within said cavity and formed with a backwardlybent terminal and extended laterally opposite said transverse thread-guide, a spring hearing upon said tension-plate and extended beneath said backwardly-bent portion of the same, a clamp-screw passing through said tension-plate and spring and into the shuttleshell, and an adjusting-screw tapped through said spring and bearing upon said shuttleshell.

In testimony that I claim the foregoing as my own 1 have hereto afiixed my signature in the presence of two Witnesses.

CHARLES H. CHITTUM.

Witnesses:

C. H. DAvIDsoN, HUGH G. WILLs. 

